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13 September 2011 Using MODIS to calibrate NOAA series AVHRR reflective solar channels
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Nearly 30 years of continuous observations made by a series of AVHRR sensors have offered a great potential for studies of global environment and climate change. In order to achieve this objective, each sensor must be accurately and consistently calibrated. This is not an easy task as there is no onboard calibrator for AVHRR reflective solar channels and vicarious calibration often needs to accumulate enough observations to derive useful trends. In this study, we select CEOS (the Committee on Earth Observation Satellites) endorsed Cal/Val desert sites to track the long-term stability of reflective solar channels of NOAA-17 AVHRR (launched on June 24, 2002) and re-calibrate them using well-calibrated MODIS as reference. A site-specific Bi-directional Reflectance Distribution Function (BRDF) developed based on observations made by MODIS is used to normalize AVHRR observed reflectances. Impacts of atmospheric water vapor on AVHRR to MODIS reflectance ratios are corrected with measured total water vapor contents derived from the split-window temperature difference technique. Finally, MODIS-based AVHRR calibration coefficients on top of the AVHRR prelaunch values are provided in time-dependent look-up tables (LUT). A further validation is performed using MODIS and AVHRR observations obtained over Antarctic Dome C site where impact due to atmospheric water vapor is negligibly small.
© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
A. Wu, A. Angal, and X. Xiong "Using MODIS to calibrate NOAA series AVHRR reflective solar channels", Proc. SPIE 8153, Earth Observing Systems XVI, 815317 (13 September 2011);

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